WHAT GASPER NOÉ had in mind was something basic. "Why not a film about rape and revenge," Noé asks in the production notes, "like Mad Max?" He even proposed a poster screaming, "Vengeance Is Man's Right," and I suppose he would claim it was meant ironically if anyone protested. In Irreversible, he's made a real gorge riser. It's a film I couldn't stand to watch but couldn't look away from. While it's hypocritical to deny how powerful it is, it's worse than hypocritical not to address the essential viciousness of Irreversible. This is the first French movie ever to play at Sundance, and that says as much about what kind of thing Sundance is as it does about the level of shock in Irreversible.

The film is essentially a grind-house version of Memento. The story runs from effect to cause, with the middle of the movie as the turning point. Alex (the pretty, voluptuous Monica Bellucci) is anally raped for about 15 minutes in a tunnel in the east Paris district of Belleville. The rapist is called Le Tenia (Jo Prestia), which means "The Tapeworm"; he's called that because he's so fond of being up people's asses. The Tapeworm is gay, but he's a rapist--that'll make him doubly disgusting to the most sexually repressed members of the audience. The Tapeworm's sodomite lust is such that he doesn't care which sex he assaults.

Irreversible opens with the raped girl's boyfriend, Marcus (Vincent Cassel), tracking the fleeing pervert. He's run aground in an S&M joint called Rectum. The film ends, or rather begins, some 12 hours earlier with Alex sunning herself in a park. Noe can't be accused of sexualizing Alex before her degradation; it happens afterward. She gets raped before we get to know her. So Noe can defend himself as an artist who has presented the whole of human experience from tenderness to violence. But has he? The scenes in Rectum are cartoonish. This filthy hellhole is lit with red light; swirls of horror-movie organ play on the soundtrack. Maybe this is what Daredevil should have looked like. It's comic, with the S&M bottoms yelling at Marcus, demanding to be fisted. San Francisco sure spoils a person: our slaves know enough to speak only when they're spoken to. When Alex wanders into the fateful tunnel, it's dumber than the teens making out in the car in a Friday the 13th picture. How could she not know what was going to happen--hadn't she seen any movies?

Other furious but inconsequential passages: Marcus belaboring a Chinese cab driver for a time-wasting 10 minutes; a long sequence establishing that Alex's previous lover, Pierre (Albert Dupontel), was a numb nut--too much the dithering French intellectual, Noé implies, unready when the rapists are out there. A love scene between Alex and Marcus foreshadows the assault; he's roughhousing and teasing her about anal sex the fateful day of the night she'll be raped. All men are tarred from the same brush, this film moans. All of us have wolves inside us. So true? Or, so what? Irreversible certainly is what it is. The problem is, it isn't more than just what it is.

Irreversible (Unrated; 99 min.), directed and written by Gaspar Noé, photographed by Benoît Debie and Noé and starring Monica Bellucci, Vincent Cassel and Jo Prestia, opens Friday at Camera One in San Jose.